1Password not loading at start-up

PS. I have tried unticking "Start at Login" in 1Password settings. When I do that, the computer starts faster but a) when I start 1Password manually, I still get the spinning wheel and "1Password not responding" message for a while and b) if I try to launch Safari before I have launched 1Password and waited for the spinning wheel to stop, Safari refuses to respond.
I'm guessing there may be a problem with the interaction between 1Password and the Safari 1Password extension - but that wouldn't explain the startup problems?